[unreadable] X-ray based technology plays a critical and important role in healthcare and biomedical research. X-ray radiography is one of the most important and widely deployed medical diagnostic methods that can be traced back to the invention of x-rays more than 100 years ago. X-ray protein crystallography is the single most useful tool to determine macromolecule structures such as proteins, especially for molecular weights above about 30kD. Recently, soft x-ray cryo-microscopy has been demonstrated to offer non-destructive high resolution three dimensional tomographic imaging of single biological cells with a resolution of about 25 nm in 2-D and 60 nm in 3-D. Important trace elements in a biological specimen such as a cell or tissue can be mapped with sensitivity better than parts per billion at a spatial resolution of about 100 nm using a synchrotron based x-ray fluorescence microscope developed by the PI and his colleagues at Argonne National Laboratory. We propose to develop a 'fast' x-ray lens that will drastically improve the performance of all the x-ray techniques described above, which are limited by the currently available x-ray lenses. The proposed 'fast' x-ray lens is a diffractive zone plate lens with an outermost zone width of about 7 nm and with a thickness optimized for a desired x-ray energy working over a large range of energies. We propose to complete the project in two phases. The goal of the phase I project is to demonstrate the technical feasibility of the proposed technical approach and the goal of the phase II project is to fabricate prototype zone plates with a 7 nm outermost zone width with a desired thickness not limited by the fabrication technique. [unreadable] [unreadable]